下面的代码示例演示如何使用异步操作将文件上载到 FTP 服务器。 using System; using System.Net; using System.Threading;using System.IO; namespace Examples.System.Net { public class FtpState { private ManualResetEvent wait; private FtpWebRequest request; private string fileName; private Exception operationException = null; string status; public FtpState() { wait = new ManualResetEvent(false); } public ManualResetEvent OperationComplete { get {return wait;} } public FtpWebRequest Request { get {return request;} set {request = value;} } public string FileName { get {return fileName;} set {fileName = value;} } public Exception OperationException { get {return operationException;} set {operationException = value;} } public string StatusDescription { get {return status;} set {status = value;} } } public class AsynchronousFtpUpLoader { // Command line arguments are two strings: // 1. The url that is the name of the file being uploaded to the server. // 2. The name of the file on the local machine. // public static void Main(string[] args) { // Create a Uri instance with the specified URI string. // If the URI is not correctly formed, the Uri constructor // will throw an exception. ManualResetEvent waitObject; Uri target = new Uri (args[0]); string fileName = args[1]; FtpState state = new FtpState(); FtpWebRequest request = (FtpWebRequest)WebRequest.Create(target); request.Method = WebRequestMethods.Ftp.UploadFile; // This example uses anonymous logon. // The request is anonymous by default; the credential does not have to be specified. // The example specifies the credential only to // control how actions are logged on the server. request.Credentials = new NetworkCredential ("anonymous","[email protected]"); // Store the request in the object that we pass into the // asynchronous operations. state.Request = request; state.FileName = fileName; // Get the event to wait on. waitObject = state.OperationComplete; // Asynchronously get the stream for the file contents. request.BeginGetRequestStream( new AsyncCallback (EndGetStreamCallback), state ); // Block the current thread until all operations are complete. waitObject.WaitOne(); // The operations either completed or threw an exception. if (state.OperationException != null) { throw state.OperationException; } else { Console.WriteLine("The operation completed - {0}", state.StatusDescription); } } private static void EndGetStreamCallback(IAsyncResult ar) { FtpState state = (FtpState) ar.AsyncState; Stream requestStream = null; // End the asynchronous call to get the request stream. try { requestStream = state.Request.EndGetRequestStream(ar); // Copy the file contents to the request stream. const int bufferLength = 2048; byte[] buffer = new byte[bufferLength]; int count = 0; int readBytes = 0; FileStream stream = File.OpenRead(state.FileName); do { readBytes = stream.Read(buffer, 0, bufferLength); requestStream.Write(buffer, 0, readBytes); count += readBytes; } while (readBytes != 0); Console.WriteLine ("Writing {0} bytes to the stream.", count); // IMPORTANT: Close the request stream before sending the request. requestStream.Close(); // Asynchronously get the response to the upload request. state.Request.BeginGetResponse( new AsyncCallback (EndGetResponseCallback), state ); } // Return exceptions to the main application thread. catch (Exception e) { Console.WriteLine("Could not get the request stream."); state.OperationException = e; state.OperationComplete.Set(); return; } } // The EndGetResponseCallback method // completes a call to BeginGetResponse. private static void EndGetResponseCallback(IAsyncResult ar) { FtpState state = (FtpState) ar.AsyncState; FtpWebResponse response = null; try { response = (FtpWebResponse) state.Request.EndGetResponse(ar); response.Close(); state.StatusDescription = response.StatusDescription; // Signal the main application thread that // the operation is complete. state.OperationComplete.Set(); } // Return exceptions to the main application thread. catch (Exception e) { Console.WriteLine ("Error getting response."); state.OperationException = e; state.OperationComplete.Set(); } } } }
using System;
using System.Net;
using System.Threading;using System.IO;
namespace Examples.System.Net
{
public class FtpState
{
private ManualResetEvent wait;
private FtpWebRequest request;
private string fileName;
private Exception operationException = null;
string status; public FtpState()
{
wait = new ManualResetEvent(false);
} public ManualResetEvent OperationComplete
{
get {return wait;}
} public FtpWebRequest Request
{
get {return request;}
set {request = value;}
} public string FileName
{
get {return fileName;}
set {fileName = value;}
}
public Exception OperationException
{
get {return operationException;}
set {operationException = value;}
}
public string StatusDescription
{
get {return status;}
set {status = value;}
}
}
public class AsynchronousFtpUpLoader
{
// Command line arguments are two strings:
// 1. The url that is the name of the file being uploaded to the server.
// 2. The name of the file on the local machine.
//
public static void Main(string[] args)
{
// Create a Uri instance with the specified URI string.
// If the URI is not correctly formed, the Uri constructor
// will throw an exception.
ManualResetEvent waitObject; Uri target = new Uri (args[0]);
string fileName = args[1];
FtpState state = new FtpState();
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(target);
request.Method = WebRequestMethods.Ftp.UploadFile; // This example uses anonymous logon.
// The request is anonymous by default; the credential does not have to be specified.
// The example specifies the credential only to
// control how actions are logged on the server. request.Credentials = new NetworkCredential ("anonymous","[email protected]"); // Store the request in the object that we pass into the
// asynchronous operations.
state.Request = request;
state.FileName = fileName; // Get the event to wait on.
waitObject = state.OperationComplete; // Asynchronously get the stream for the file contents.
request.BeginGetRequestStream(
new AsyncCallback (EndGetStreamCallback),
state
); // Block the current thread until all operations are complete.
waitObject.WaitOne(); // The operations either completed or threw an exception.
if (state.OperationException != null)
{
throw state.OperationException;
}
else
{
Console.WriteLine("The operation completed - {0}", state.StatusDescription);
}
}
private static void EndGetStreamCallback(IAsyncResult ar)
{
FtpState state = (FtpState) ar.AsyncState; Stream requestStream = null;
// End the asynchronous call to get the request stream.
try
{
requestStream = state.Request.EndGetRequestStream(ar);
// Copy the file contents to the request stream.
const int bufferLength = 2048;
byte[] buffer = new byte[bufferLength];
int count = 0;
int readBytes = 0;
FileStream stream = File.OpenRead(state.FileName);
do
{
readBytes = stream.Read(buffer, 0, bufferLength);
requestStream.Write(buffer, 0, readBytes);
count += readBytes;
}
while (readBytes != 0);
Console.WriteLine ("Writing {0} bytes to the stream.", count);
// IMPORTANT: Close the request stream before sending the request.
requestStream.Close();
// Asynchronously get the response to the upload request.
state.Request.BeginGetResponse(
new AsyncCallback (EndGetResponseCallback),
state
);
}
// Return exceptions to the main application thread.
catch (Exception e)
{
Console.WriteLine("Could not get the request stream.");
state.OperationException = e;
state.OperationComplete.Set();
return;
} } // The EndGetResponseCallback method
// completes a call to BeginGetResponse.
private static void EndGetResponseCallback(IAsyncResult ar)
{
FtpState state = (FtpState) ar.AsyncState;
FtpWebResponse response = null;
try
{
response = (FtpWebResponse) state.Request.EndGetResponse(ar);
response.Close();
state.StatusDescription = response.StatusDescription;
// Signal the main application thread that
// the operation is complete.
state.OperationComplete.Set();
}
// Return exceptions to the main application thread.
catch (Exception e)
{
Console.WriteLine ("Error getting response.");
state.OperationException = e;
state.OperationComplete.Set();
}
}
}
}